<template>
  <div>
    <el-switch v-model="draggable" active-text="开启拖拽" inactive-text="关闭拖拽"></el-switch>
    <el-button v-if="draggable" @click="batchSave">批量保存</el-button>
    <el-button type="danger" @click="batchDelete">批量删除</el-button>
    <el-tree
      :data="menus"
      :props="defaultProps"
      :expand-on-click-node="false"
      show-checkbox
      node-key="catId"
      :default-expanded-keys="expandedKey"
      :draggable="draggable"
      :allow-drop="allowDrop"
      @node-drop="handleDrop"
      ref="menuTree"
    >
      <span class="custom-tree-node" slot-scope="{ node, data }">
        <span>{{ node.label }}</span>
        <span>
          <el-button
            v-if="node.level <=2"
            type="text"
            size="mini"
            @click="() => append(data)"
          >Append</el-button>
          <el-button type="text" size="mini" @click="edit(data)">edit</el-button>
          <el-button
            v-if="node.childNodes.length==0"
            type="text"
            size="mini"
            @click="() => remove(node, data)"
          >Delete</el-button>
        </span>
      </span>
    </el-tree>

    <el-dialog
      :title="title"
      :visible.sync="dialogVisible"
      width="30%"
      :close-on-click-modal="false"
    >
      <el-form :model="category">
        <el-form-item label="分类名称">
          <el-input v-model="category.name" autocomplete="off"></el-input>
        </el-form-item>
        <el-form-item label="图标">
          <el-input v-model="category.icon" autocomplete="off"></el-input>
        </el-form-item>
        <el-form-item label="计量单位">
          <el-input v-model="category.productUnit" autocomplete="off"></el-input>
        </el-form-item>
      </el-form>
      <span slot="footer" class="dialog-footer">
        <el-button @click="dialogVisible = false">取 消</el-button>
        <el-button type="primary" @click="submitData">确 定</el-button>
      </span>
    </el-dialog>
  </div>
</template>

<script>
//  这里可以导入其他文件（比如：组件，工具js，第三方插件js，json文件，图片文件等等）
export default {
  //  import引入的组件需要注入到对象中才能使用
  components: {},
  props: {},
  data () {
    return {
      pCid: [],
      draggable: false,
      updateNodes: [],
      maxLevel: 0,
      title: '',
      dialogType: '', //  edit,add
      category: {
        name: '',
        parentCid: 0,
        catLevel: 0,
        showStatus: 1,
        sort: 0,
        productUnit: '',
        icon: '',
        catId: null,
      },
      dialogVisible: false,
      menus: [],
      expandedKey: [],
      defaultProps: {
        children: 'childrenMenu',
        label: 'name',
      },
    }
  },
  methods: {
    getMenus () {
      this.$http({
        url: this.$http.adornUrl('/product/category/list/tree'),
        method: 'get',
      }).then(({ data }) => {
        console.log('成功获取到菜单数据...', data.data)
        this.menus = data.data
      })
    },
    batchDelete () {
      let catIds = []
      let checkedNodes = this.$refs.menuTree.getCheckedNodes()
      console.log('被选中的元素', checkedNodes)
      for (let i = 0; i < checkedNodes.length; i++) {
        catIds.push(checkedNodes[i].catId)
      }
      this.$confirm(`是否批量删除【${catIds}】菜单?`, '提示', {
        confirmButtonText: '确定',
        cancelButtonText: '取消',
        type: 'warning',
      }).then(() => {
        this.$http({
          url: this.$http.adornUrl('/product/category/delete'),
          method: 'post',
          data: this.$http.adornData(catIds, false),
        }).then(({ data }) => {
          this.$message({
            message: '菜单批量删除成功',
            type: 'success',
          })
          this.getMenus()
        })
      }).catch(() => {
      })
    },
    batchSave () {
      this.$http({
        url: this.$http.adornUrl('/product/category/update/sort'),
        method: 'post',
        data: this.$http.adornData(this.updateNodes, false),
      }).then(({ data }) => {
        this.$message({
          message: '菜单顺序等修改成功',
          type: 'success',
        })
        //  刷新出新的菜单
        this.getMenus()
        //  设置需要默认展开的菜单
        this.expandedKey = this.pCid
        this.updateNodes = []
        this.maxLevel = 0
        //  this.pCid = 0;
      })
    },
    handleDrop (draggingNode, dropNode, dropType, ev) {
      console.log('handleDrop: ', draggingNode, dropNode, dropType)
      //  1、当前节点最新的父节点id
      let pCid = 0
      let siblings = null
      if (dropType === 'before' || dropType === 'after') {
        pCid = dropNode.parent.data.catId === undefined ? 0 : dropNode.parent.data.catId
        siblings = dropNode.parent.childNodes
      } else {
        pCid = dropNode.data.catId
        siblings = dropNode.childNodes
      }
      this.pCid.push(pCid)

      //  2、当前拖拽节点的最新顺序
      for (let i = 0; i < siblings.length; i++) {
        if (siblings[i].data.catId === draggingNode.data.catId) {
          //  如果遍历的是当前正在拖拽的节点
          let catLevel = draggingNode.level
          if (siblings[i].level !== draggingNode.level) {
            //  当前节点的层级发生变化
            catLevel = siblings[i].level
            //  修改他子节点的层级
            this.updateChildNodeLevel(siblings[i])
          }
          this.updateNodes.push({
            catId: siblings[i].data.catId,
            sort: i,
            parentCid: pCid,
            catLevel: catLevel,
          })
        } else {
          this.updateNodes.push({ catId: siblings[i].data.catId, sort: i })
        }
      }

      //  3、当前拖拽节点的最新层级
      console.log('updateNodes', this.updateNodes)
    },
    updateChildNodeLevel (node) {
      if (node.childNodes.length > 0) {
        for (let i = 0; i < node.childNodes.length; i++) {
          var cNode = node.childNodes[i].data
          this.updateNodes.push({
            catId: cNode.catId,
            catLevel: node.childNodes[i].level,
          })
          this.updateChildNodeLevel(node.childNodes[i])
        }
      }
    },
    //  拖拽时判定目标节点能否被放置。type 参数有三种情况：'prev'、'inner' 和 'next'，
    //  分别表示放置在目标节点前、插入至目标节点和放置在目标节点后
    allowDrop (draggingNode, dropNode, type) {
      //  1、被拖动的当前节点以及所在的父节点总层数不能大于3

      //  1）、被拖动的当前节点总层数
      console.log('allowDrop:', draggingNode, dropNode, type)
      //
      this.countNodeLevel(draggingNode)
      //  当前正在拖动的节点+父节点所在的深度不大于3即可
      let deep = Math.abs(this.maxLevel - draggingNode.level) + 1
      console.log('深度：', deep)

      //    this.maxLevel
      if (type === 'inner') {
        //  console.log(
        //    `this.maxLevel：${this.maxLevel}；draggingNode.data.catLevel：${draggingNode.data.catLevel}；dropNode.level：${dropNode.level}`
        //  );
        return deep + dropNode.level <= 3
      } else {
        return deep + dropNode.parent.level <= 3
      }
    },
    countNodeLevel (node) {
      //  找到所有子节点，求出最大深度
      if (node.childNodes != null && node.childNodes.length > 0) {
        for (let i = 0; i < node.childNodes.length; i++) {
          if (node.childNodes[i].level > this.maxLevel) {
            this.maxLevel = node.childNodes[i].level
          }
          this.countNodeLevel(node.childNodes[i])
        }
      }
      if (this.maxLevel === 0) {
        this.maxLevel = 3
      }
    },
    edit (data) {
      console.log('要修改的数据', data)
      this.dialogType = 'edit'
      this.title = '修改分类'
      this.dialogVisible = true

      //  发送请求获取当前节点最新的数据
      this.$http({
        url: this.$http.adornUrl(`/product/category/info/${data.catId}`),
        method: 'get',
      }).then(({ data }) => {
        //  请求成功
        console.log('要回显的数据', data)
        this.category.name = data.data.name
        this.category.catId = data.data.catId
        this.category.icon = data.data.icon
        this.category.productUnit = data.data.productUnit
        this.category.parentCid = data.data.parentCid
        this.category.catLevel = data.data.catLevel
        this.category.sort = data.data.sort
        this.category.showStatus = data.data.showStatus
        /**
         *         parentCid: 0,
         catLevel: 0,
         showStatus: 1,
         sort: 0,
         */
      })
    },
    append (data) {
      console.log('append', data)
      this.dialogType = 'add'
      this.title = '添加分类'
      this.dialogVisible = true
      this.category.parentCid = data.catId
      this.category.catLevel = data.catLevel * 1 + 1
      this.category.catId = null
      this.category.name = ''
      this.category.icon = ''
      this.category.productUnit = ''
      this.category.sort = 0
      this.category.showStatus = 1
    },

    submitData () {
      if (this.dialogType === 'add') {
        this.addCategory()
      }
      if (this.dialogType === 'edit') {
        this.editCategory()
      }
    },
    //  修改三级分类数据
    editCategory () {
      var { catId, name, icon, productUnit } = this.category
      this.$http({
        url: this.$http.adornUrl('/product/category/update'),
        method: 'post',
        data: this.$http.adornData({ catId, name, icon, productUnit }, false),
      }).then(({ data }) => {
        this.$message({
          message: '菜单修改成功',
          type: 'success',
        })
        //  关闭对话框
        this.dialogVisible = false
        //  刷新出新的菜单
        this.getMenus()
        //  设置需要默认展开的菜单
        this.expandedKey = [this.category.parentCid]
      })
    },
    //  添加三级分类
    addCategory () {
      console.log('提交的三级分类数据', this.category)
      this.$http({
        url: this.$http.adornUrl('/product/category/save'),
        method: 'post',
        data: this.$http.adornData(this.category, false),
      }).then(({ data }) => {
        this.$message({
          message: '菜单保存成功',
          type: 'success',
        })
        //  关闭对话框
        this.dialogVisible = false
        //  刷新出新的菜单
        this.getMenus()
        //  设置需要默认展开的菜单
        this.expandedKey = [this.category.parentCid]
      })
    },

    remove (node, data) {
      var ids = [data.catId]
      this.$confirm(`是否删除【${data.name}】菜单?`, '提示', {
        confirmButtonText: '确定',
        cancelButtonText: '取消',
        type: 'warning',
      }).then(() => {
        this.$http({
          url: this.$http.adornUrl('/product/category/delete'),
          method: 'post',
          data: this.$http.adornData(ids, false),
        }).then(({ data }) => {
          this.$message({
            message: '菜单删除成功',
            type: 'success',
          })
          //  刷新出新的菜单
          this.getMenus()
          //  设置需要默认展开的菜单
          this.expandedKey = [node.parent.data.catId]
        })
      }).catch(() => {
      })

      console.log('remove', node, data)
    },
  },
  //  生命周期-创建完成（可以访问当前this实例）
  created () {
    this.getMenus()
  },
}
</script>
<style scoped>
</style>
